1. Technical Field
The present disclosure relates generally to an apparatus and method for collecting the radio frequency (RF) feature of a wireless device in a wireless communication apparatus and, more particularly, to an apparatus and method for collecting information about the RF feature of a wireless device that can send and receive radio waves over a wireless local area network (WLAN).
2. Description of the Related Art
A WLAN is a network that wirelessly offers data communication between computers using radio waves without requiring a physical communication line. Recently, thanks to the rapid development of wireless communication technology, such as 802.11n and 802.11ac, and an explosive increase in wireless devices (e.g., mobile devices) using a WLAN, the importance of a WLAN has further increased.
However, security vulnerability inherent in a WLAN has become an obstacle to the active use of a WLAN. One representative security problem in a current WLAN environment is an ID weakness problem. A wireless device refers to a communication device, such as a smart phone or an access point (AP), on a WLAN.
In general, a medium access control (MAC) address, that is, an ID of a network second layer, is chiefly used as an ID that is used to identify a wireless device on a WLAN. An MAC address is frequently used as a certification and authentication mechanism on the 802.11 wireless network because it can globally identify a network device. However, there is a need for a method that is capable of detecting and defending a MAC address spoofing attack because such a MAC address may be easily manipulated by an attacker.
One current best method for detecting a MAC address spoofing attack is a method of identifying a wireless device using an RF feature. In the method of identifying a wireless device based on an RF feature, a wireless device is uniquely identified based on RF information, such as a modulation error and a signal transmission transient shape, which is generated due to a minute difference between hardware elements in each wireless device. The modulation error is information that is generated when a wireless device that sends data modulates a digital signal into an analog signal. Information for measuring a modulation error includes EVM, a frame frequency error, an I/Q origin offset, and a sync correlation. The signal transmission transient shape refers to information about signal transition between a point of time at which a packet starts to be transmitted and a point of time at which a signal corresponding to the packet is actually transmitted. Accordingly, in order to identify a wireless device, the MAC address and RF feature information of the wireless device need to be collected.
FIG. 1 is a block diagram illustrating the configuration of a typical wireless communication apparatus.
The typical wireless communication apparatus of FIG. 1 includes an RF processing unit 1 configured to process a wireless analog signal to be transmitted or having been received, an analog-to-digital/digital-to-analog (AD/DA) processing unit 2 configured to convert a digital signal to be transmitted into an analog signal through the RF processing unit 1 and to convert an analog signal have been received into a digital signal through the RF processing unit 1, a baseband processing unit 3 configured to perform a channel coding and modulation function on data to be transmitted through the RF processing unit 1 and perform a demodulation and error correction function on data having been received through the RF processing unit 1, and a MAC processing unit 4 configured to perform a data link processing function according to a MAC protocol.
A WLAN card that is used in a wireless AP and a wireless terminal corresponds to a wireless communication apparatus. A process in which a wireless device sends data is described below. First, the MAC processing unit 4 generates a MAC frame in which the MAC addresses of a source and a destination have been set. The baseband processing unit 3 modulates the digital MAC frame according to a channel characteristic. The AD/DA conversion unit 2 converts the digital signal into an analog signal. The RF processing unit 1 processes the generated analog signal, and sends the processed signal to the outside.
A process in which a wireless device receives data is opposite to the process of sending data. First, the RF processing unit 1 processes a received analog signal. The AD/DA conversion unit 2 converts the analog signal into a digital signal, and transfers the digital signal to the baseband processing unit 3. The baseband processing unit 3 performs a demodulation and error correction function on the digital signal. Finally, the MAC processing unit 4 processes link layer data by decoding a MAC frame.
As described above, conventionally, information about the RF feature of a wireless device is collected using a wireless measuring instrument because a wireless communication apparatus does not offer a direct function of collecting the MAC address of the wireless device and corresponding RF feature information.
The conventional method using a wireless measuring instrument may be problematic in that a wireless device identification speed is low because the RF feature of a wireless device is not collected in real time.
Accordingly, there is a need for a method and apparatus that are capable of collecting the MAC address and RF feature information of a wireless device in real time in a wireless communication apparatus. The collected RF feature information may be information of high quality at a level at which the wireless device can be accurately identified based on the information.
As an example of related art, U.S. Pat. No. 8,018,883 entitled “Wireless Transmitter Identity Validation in a Wireless Network” discloses technology in which when a radio signal is received, the RF feature of the received radio signal is determined, a network identifier (i.e., MAC address) is determined by decoding the received radio signal, the behavior feature of the received radio signal is determined, and whether the network identifier of the received radio signal has been forged is determined using the network identifier, RF feature and behavioral feature of the received radio signal.